Stand for assembling and pressing magnetic circuits of power transformers

ABSTRACT

A stand designed for assembling and pressing magnetic circuits of power transformers and comprising a turnable base mounting an assembly table which has supports for cores and yokes of the magnetic circuit, and a portable pressing beam with a drive adapted for displacing the latter beam when pressing, the supports for yokes being fashioned as transverse beams carrying jacks which serve to adjust the height of the supports.

United States Patent 1151 3,685,435 Pshenichny et al. 1451 Aug. 22, 1972 1541 STAND FOR ASSEMBLING AND 1 1 Reierences Cited 4 PRESSING MAGNETIC CIRCUITS OF UNITED STATES PATENTS POWER TRANSFORMERS 2,271,596 2/1942 Liggins ..100/3 Inventors: Gennady Ivamvich Pshenichny, ulit- 2,726,700 12/1955 Browning ..100/3 ux 8a Kremlevskaya, 27, 8; 2,966,816 1/1961 White ..100/3 ux Zinovievich Checheljuk,

Dnepropetrovskoe shosse, 48, kv.

17; Mikhail Andreevich Afanmiev,

Dnepropetrovskoe shosse, 62, kv.

65, all of Zaporozhie, U.S.S.R.

Filed: Sept. 2, 1969 Appl. No.: 854,610

US. Cl. ..l00/8, 100/3, 100/33, 100/228, 100/257, 100/295 Int. Cl. ..B65b 13/20 Field of Search ..100/3, 12, 257, 295, 228, 8, 100/33; 140/71 Primary Examiner-Billy J. Wilhite Attorney-Waters, Roditi, Schwartz 8: Nissen I [57] ABSTRACT A stand designed for assembling and pressing rnagnetic circuits of power transformers and comprising a 5 China, 4 Drawing Figures PATENTED B lH 685 4 35 SHEET 1 [IF 4. I

FIG!

PATENTEUwczz Ian 3.685.435

SHEET 2 UP 4 The present invention relates to equipment to be employed in the manufacture of transformers and, more particularly, to stands designed for assembling and pressing magnetic circuits of power transformers.

There is known in the prior art a stand for assembling and pressing single-frame magnetic circuits of power transformers with the aid of resilient tie clamps to be placed onto cores of the magnetic circuit. The stand comprises a tumable base mounting an assembly table with a system of supporting elements for cores and yokes of the magnetic circuit (onto a latter elements are placed magnetic circuit sheets in accordance with the lamination pattern); a portable pressing beam with a drive for clamping the cores of the magnetic circuit by displacement of the moveable portion of the beam, and a means adapted for tightening and securing bandages on the cores of the magnetic circuit.

The tumable base of the stand is supported by means of a plate connected to the base through the intermediary of toothed racks and levers.

In the known stand no provision has been made for a mechanized pressing of the yokes of the magnetic circuit. The yokes are pressed manually, for example, with the aid of tie pins. Additionally, when pressing magnetic circuits of high-power transformers, the long pressing beam sags in a direction opposite to that in which the pressing force is applied. This brings about an inadequate pressing of the elements of the magnetic circuit located under the middle portion of the beam, which, in turn, impairs the technical characteristics of the transformers.

The sag can be eliminated or minimized by increasing the beam cross-section, however, this will bring about a considerable increase in the mass of the pressing beam and stand elements connected thereto.

It is an object of the present invention to eliminate the afore-mentioned disadvantages of said known stands.

The invention contemplates the development of a stand designed for assembling and pressing magnetic circuits of power transformers, having supports for yokes, which will ensure the assembly and high-quality mechanized pressing of cores and yokes of mangetic circuits of mediumand high-power transformers without any considerable increase in the mass of the pressing beam and stand elements connected thereto.

The above and other objects of the present invention are accomplished in a stand designed for assembling and pressing magnetic circuits of power transformers and comprising a tumable base on which an assembly table is mounted which has supports for cores and yokes of the magnetic circuit, and a portable pressing beam with a displacing drive means therefor, wherein, according to the invention, the supports for the yokes are fashioned as transverse beams carrying jacks which serve to adjust the height of the supports.

It is advisable that the pressing beam be equipped with a supplementary power drive for the purpose of local pressing of the magnetic circuit elements in the zone of placing bandages.

The stand constructed in accordance with the invention provides for the assembly and mechanized pressing of cores and yokes of magnetic circuits of mediumand high-power transformers, and precludes the adverse effect of beam sagging upon the quality of pressing, for the supplementary power drive effects the additional pressing of the magnetic circuit in the zone of placing bandages. This permits the use of a pressing beam of a minimum permissible cross-section for pressing mag netic circuits of high-power transformers.

The specific features and advantages of this invention will appear more completely from the following detailed description of a typical embodiment thereof given by way of illustration with reference to the accompanying drawings, in which:

FIG. 1 is a side elevation view of a stand for assemmers, according to the invention; FIG. 2 is a plan view thereof;

FIG. 3 is an elevation view of a pressing beam of the stand, according to the invention; and

FIG. 4 is a longitudinal section of a supplementary power drive of the stand, according to the invention.

Referring to FIG. 1, the stand of the present invention comprises a tumable base 1 on which is mounted an assembly table 2 which has longitudinally extending beams 3 intended for mounting cores 4 of a magnetic circuit and transversely extending beams 5 for mounting yokes 20 of the magnetic circuit. The longitudinal beams 3 carry supports 6 on which there are placed sheets of the cores 4 of the magnetic circuit in accordance with the pattern of the magnetic circuit lamination. The transverse beams 5 carry jacks 7 and accommodate sheets of yokes 20 placed thereonto. A pressing beam 8 is installed on bars 9 connected to the assembly table 2. The bars 9 are received in sockets 10 (FIG. 2) provided in the longitudinal and transverse beams. Arranged at the ends of the pressing beam 8 are two power drives 11 (FIG. 3) serving to transmit pressing force to the beam 8. In addition to the drives 11, the beam 8 carries a drive 13 (FIG. 4) which is mounted on a carriage l2 and serves to produce a supplementary pressing force at the point of placing a bandage 14 or securing strap around the yokes. A rod of a piston 15 of the drive 13 carries pressing shoes 16 which transmit the pressing force to shoes 17 of the pressing beam 8. The pressing shoes 16 are spaced at such a distance from each other as to allow the feed to the place of joining the ends of the bandage 14 of a gas burner 18 for welding the bandage.

For cutting off a loose end of the bandage 14, a rod 19 passing through the rod and piston 15 is provided with a knife 20. The displacement of the piston 15 and rod 19 is effected by delivering fluid medium into chambers 21 and 22.

When pressing the yokes of the magnetic circuit, having projections or cantilevers installed thereon, there are mounted on the pressing shoes 17 detachable extension pieces (FIG. 3) in order to enable the force of the drives 11 to be transmitted to the cores and yokes of the magnetic circuit and the bars 9 are connected with attachments 24 by means of wedges 25.

The operations of assembling and pressing magnetic circuits in the proposed stands are carried out in the following manner.

Sheets of magnetic circuit cores are placed onto the supports'6 of the longitudinal beams 3 in accordance with the lamination pattern, while sheets of mag- I netic circuit yokes are placed onto the jacks 7 of the transverse beams 5. The sheets of cores and yokes are secured in position by means of stops (not shown in the drawings). Then, the bars 9 are made fast in the sockets l0, and the pressing beam 8 is mounted on the bars; A general pressing of the magnetic circuit core is effected by actuationof the drives 11, whereupon the carriage 12 is shifted to the zone of placing the first bandage,

fluid medium is delivered into the chamber 21, and the rod and piston 15, are displaced to efi'ect local pressing of the core. The core is bandaged i.e. wrapped with a' securing strap without relieving the pressing load, whereupon the bandage or strap ends are welded.

, Then, the fluid medium is delivered into the chamber 22, and the rod 19 is displaced to cut the loose end of the bandage with knife '20. Thereafter, the drive 13 is disconnected, the carriage 12 is shifted to the zone of of general'pressing and local pressing in the zone of placing bandages are efi'ected, and the pressed yoke is secured with the aid of semi-bandages. When pressing yokes without cantilevers, full bandages are placed on the yokes, as is the case with the cores.

The length of the pressing beam is selected so as to correspond to the maximum length of the cores of magnetic circuits to be assembled in the stand.

In the majority of power transformers the yokes of the magnetic circuit are considerably longer than the cores, and pressing each yoke is in some cases efiected by placing the pressing beam first over one half of the yoke and then over the other.

Following the full pressing and bandaging of the magnetic circuit, the tumable base is pivoted about an I tion has been shown and described herein, other. equivalent embodiments of the proposed standarea said transverse beams for regulating the height of the I axle l to a position'close to vertical, and the magnetic circuit is removed from the stand.

The stand of the herein proposed design makes it possible to assemble and press both cores and yokes of magnetic circuits of mediumand high-power transformers, as well as to considerably increase the quality of magnetic circuits. I

While a preferred embodiment of the present invenpossible within the scope of .the invention-as the appended claims We claim: I g l. A stand for assembling and pressing magnetic cirdefined by cuits of power transformers and having a base which is tumable from a horizontal position to a tilted position,

said stand comprising: an assembly table mounted on said base; longitudinal beams on said table for support of cores for said circuit; transverse beams on said table for support of yokes for said circuit; a pressing beam mounted on said beams above said table and means for displacing said pressing'beam towards said table to yokes.

3. A stand as claimed in claim 2 comprising asecond means on said pressing beams independent of the first means, for applying local pressing force against the cores and yokes, and means for displacing the second means on said pressing beam to control the location of i the application of the local pressing force.

4. A stand as claimed in claim 3 comprising a plurality of shoes on saidpr'essing beam spaced along the length thereof, said second means comprising a piston rod and further shoes on said rod for selective engagement with the shoes on the pressing beam. 7

5. A stand as claimed in claim 4 comprising cutting.

means for severing the ends of a bandage wrapped around the yokes of said circuit, said cutting means being connected to and operated by said second means. 7

okes, 1 c0 prrsrng acks on 

1. A stand for assembling and pressing magnetic circuits of power transformers and having a base which is turnable from a horizontal position to a tilted position, said stand comprising: an assembly table mounted on said base; longitudinal beams on said table for support of cores for said circuit; transverse beams on said table for support of yokes for said circuit; a pressing beam mounted on said beams above said table and means for displacing said pressing beam towards said table to press said beam against the cores and yokes.
 2. A stand as claimed in claim 1 comprising jacks on said transverse beams for regulating the height of the yokes.
 3. A stand as claimed in claim 2 comprising a second means on said pressing beams independent of the first means, for applying local pressing force against the cores and yokes, and means for displacing the second means on said pressing beam to control the location of the application of the local pressing force.
 4. A stand as claimed in claim 3 comprising a plurality of shoes on said pressing beam spaced along the length thereof, said second means comprising a piston rod and further shoes on said rod for selective engagement with the shoes on the pressing beam.
 5. A stand as claimed in claim 4 comprising cutting means for severing the ends of a bandage wrapped around the yokes of said circuit, said cutting means being connected to and operated by said second means. 